This non-provisional application claims priority under 35 U.S.C. § 119(a) on Korean Patent Application No. 10-2006-0138714 filed on Dec. 29, 2006, which is herein incorporated by reference.
1. Field of the Invention
The present invention relates to a method for producing tetrahydrofuran (THF) from 1,4-butanediol (BDO). More specifically, the present invention relates to a method for producing tetrahydrofuran in high yield from 1,4-butanediol using a zirconium sulfate (Zr(SO4)2.nH2O) catalyst.
2. Description of the Related Art
Tetrahydrofuran has been widely used in various fields including as a solvent of organic compounds or a starting material for polymer synthesis. Recently, use of tetrahydrofuran has gradually increased with finding its application as a starting material and an additive to synthetic polymers. Tetrahydrofuran has been produced by various processes.
Generally, tetrahydrofuran is obtained by dehydration of 1,4-butanediol or hydrogenation of furan. The dehydration of 1,4-butanediol is carried out by two steps including reacting 1,4-butanediol in the presence of an acid catalyst and then removing water from the water-containing reaction product, e.g. tetrahydrofuran. The yield of the process is determined by the performance of the acid catalyst used in the reaction, so research has continuously been required to develop effective catalysts for use in dehydration of 1,4-butanediol. U.S. Pat. No. 4,665,205 discloses a dehydration process of 1,4-butanediol using an inorganic acid catalyst such as sulfuric acid. However, the above process has problems that inorganic acid is dangerous to handle and the reactor is corroded by the inorganic acid.
Further, there are methods of producing tetrahydrofuran from 1,4-butanediol in the presence-of several acid catalysts, e.g. U.S. Pat. No. 6,204,399, Japanese Unexamined Patent Publication No. Hei 09-059191, U.S. Pat. No. 4,136,099, and Japanese Unexamined Patent Publication No. Sho 61-126080 disclose dehydration reactions of 1,4-butanediol using an alumina catalyst, a silica-alumina catalyst, an alumina-supported tungsten oxide catalyst, and a heteropolyacid catalyst, respectively. However, these methods also suffer from disadvantages associated with the activity and stability of the catalysts.